DE112018001087T5 - Electric wire, coil and method of making an electrical wire - Google Patents

Abstract

It is intended to provide an electric wire and a coil covered with a cured product of a thermosetting or light-curable fluorinated polymer and having very good insulating properties and high productivity. An electrical wire comprises a conductor wire and a cover layer covering the outer periphery of the conductor wire, wherein the cover layer is made of a cured product of a curable composition comprising a fluorinated polymer containing at least three functional groups represented by the following formula (F (in formula (F) is pure single bond, a fluoroalkylene group or a fluoroalkylene group having at least two carbon atoms with an ether oxygen atom between carbon-carbon atoms, Zist NRNRH, NRORor OR, and R, R, R, R are each Rc independently a hydrogen atom or an alkyl group.)

Description

TECHNICAL AREA

The present invention relates to an electric wire, a coil using the same, and a method of manufacturing the electric wire.

STATE OF THE ART

To promote downsizing and weight reduction of mobile devices, automobiles, etc., electrical wires or cables used for these applications must have reduced diameters. Accordingly, it is necessary to form a capping layer made of an insulating material covering the core wire (i.e., the inner conductor) with a small thickness.

Heretofore, a liquid insulating varnish having a thermosetting resin dissolved in a solvent has been used for producing a wire enamel wire for use with a winding wire. For producing a wire enamel wire using the liquid insulating varnish, a core wire is dipped in and covered with the liquid insulating varnish, whereupon it is baked and heat-cured to form a covering layer. In such a case, the thickness of the capping layer may be e.g. can be reduced by adjusting the concentration of the thermosetting resin in the liquid insulating varnish. In recent years, in order to increase the productivity in Patent Document 1, a polyimide composition containing a photo-curable polyimide has been proposed as a liquid insulating varnish.

On the other hand, in the case of an electric wire other than a winding wire, a core wire is usually covered by extrusion molding a thermoplastic resin. In Patent Document 2, a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer, which is a fluorinated resin having a low relative dielectric constant and which can be made thin, has been proposed to reduce a transmission loss.

DOCUMENTS OF THE PRIOR ART

PATENT DOCUMENTS

• Patent Document 1: WO 2015/129913
• Patent Document 2: Japanese Patent No. 4,591,352

DISCLOSURE OF THE INVENTION

TECHNICAL PROBLEM

However, the thermosetting resin used in the liquid insulating varnish disclosed in Patent Document 1 had inferior insulating properties than a fluorinated resin, especially a perfluororesin. On the other hand, extrusion molding of the fluorinated resin disclosed in Patent Document 2 requires an expensive molding machine resistant to acid components generated during molding.

It is an object of the present invention to provide an electric wire and a coil covered with a cured product of a thermosetting or photocurable fluorinated polymer and having very good insulating properties and high productivity. It is another object of the present invention to provide a method of manufacturing an electric wire with which it is possible to manufacture an electrical wire having very good insulating properties by a simple device.

THE SOLUTION OF THE PROBLEM

1. [1] Elektrischer Draht, der einen Leiterdraht und eine Abdeckungsschicht, die den Außenumfang des Leiterdrahts bedeckt, umfasst, wobei die Abdeckungsschicht aus einem ausgehärteten Produkt einer aushärtbaren Zusammensetzung hergestellt ist, die ein fluoriertes Polymer enthält, das mindestens drei funktionelle Gruppen enthält, die durch die folgende Formel (F) dargestellt sind: -R^f1COZ¹ (F) (in der Formel (F) ist R^f1 eine Einfachbindung, eine Fluoralkylengruppe oder eine Fluoralkylengruppe mit mindestens zwei Kohlenstoffatomen mit einem Ethersauerstoffatom zwischen Kohlenstoff-Kohlenstoff-Atomen, Z¹ ist NR¹NR²H, NR³OR⁴ oder OR⁵, und R¹, R², R³, R⁴ und R⁵ sind jeweils unabhängig ein Wasserstoffatom oder eine Alkylgruppe.)
2. [2] Elektrischer Draht nach [1], bei dem das fluorierte Polymer mindestens eine der funktionellen Gruppen, die durch die Formel (F) dargestellt sind, in einer Einheit enthält, die durch die folgende Formel (U1) dargestellt ist:
   
   (in der Formel (U1) sind X¹ und X² jeweils unabhängig ein Wasserstoffatom oder ein Fluoratom, Q¹ ist eine Einfachbindung oder ein Ethersauerstoffatom, R^f1 ist eine Einfachbindung, eine Fluoralkylengruppe oder eine Fluoralkylengruppe mit mindestens zwei Kohlenstoffatomen mit einem Ethersauerstoffatom zwischen Kohlenstoff-Kohlenstoff-Atomen, Z¹ ist NR¹NR²H, NR³OR⁴ oder OR⁵, und R¹, R², R³, R⁴ und R⁵ sind jeweils unabhängig ein Wasserstoffatom oder eine Alkylgruppe.)
3. [3] Elektrischer Draht nach [2], bei dem das fluorierte Polymer mindestens drei Einheiten enthält, die durch die Formel (U1) dargestellt sind.
4. [4] Elektrischer Draht nach [1], bei dem das fluorierte Polymer mindestens drei Gruppen enthält, die durch die folgende Formel (F1) dargestellt sind: -(R^f2O)_k-R^f1COZ¹ (F1) (in der Formel (F1) ist R^f2 eine C_1-4-Perfluoralkylengruppe; k ist eine ganze Zahl von 1 bis 200; R^f1 ist eine Einfachbindung, eine Fluoralkylengruppe oder eine Fluoralkylengruppe mit mindestens zwei Kohlenstoffatomen mit einem Ethersauerstoffatom zwischen Kohlenstoff-Kohlenstoff-Atomen; Z¹ ist NR¹NR²H, NR³OR⁴ oder OR⁵; und R¹, R², R³, R⁴ und R⁵ sind jeweils unabhängig ein Wasserstoffatom oder eine Alkylgruppe.)
5. [5] Elektrischer Draht nach [4], bei dem das fluorierte Polymer eine Verbindung ist, in der drei oder vier Gruppen, die durch die Formel (F1) dargestellt sind, an ein Kohlenstoffatom gebunden sind.
6. [6] Elektrischer Draht nach einem von [1] bis [5], bei dem die Menge von Fluoratomen, die in dem fluorierten Polymer enthalten sind, von 50 bis 76 Massen-% beträgt.
7. [7] Elektrischer Draht nach einem von [1] bis [6], bei dem der Leiterdraht aus einem Kupferleiter oder einem Aluminiumleiter hergestellt ist.
8. [8] Verfahren zur Herstellung des elektrischen Drahts nach einem von [1] bis [7], gekennzeichnet durch Bedecken des Außenumfangs des Leiterdrahts mit der aushärtbaren Zusammensetzung zur Bildung einer Vorstufenschicht der Abdeckungsschicht, und Anwenden von Wärme und/oder Einstrahlen von aktiven Energiestrahlen auf die Vorstufenschicht, so dass eine Abdeckungsschicht erhalten wird, die aus einem ausgehärteten Produkt der aushärtbaren Zusammensetzung hergestellt ist.
9. [9] Verfahren zur Herstellung des elektrischen Drahts nach [8], bei dem die Vorstufenschicht durch Aufbringen einer Beschichtungszusammensetzung, welche die aushärtbare Zusammensetzung und eine Flüssigkeit mit einem Siedepunkt von höchstens 250 °C umfasst, auf den Außenumfang des Leiterdrahts und Verflüchtigen der Flüssigkeit von der aufgebrachten Beschichtungszusammensetzung ausgebildet wird.
10. [10] Spule, die durch Formen des elektrischen Drahts nach einem von [1] bis [7] zu einer Spulenform ausgebildet worden ist.

The present invention provides an electric wire, a method of manufacturing the same, and a coil having the following structure [1] to [10].

1. [1] An electric wire comprising a conductor wire and a cover layer covering the outer circumference of the conductor wire, wherein the cover layer is made of a cured product of a curable composition containing a fluorinated polymer containing at least three functional groups, which is substituted by the following formula (F) are shown: -R ^f1 COZ ¹ (F) (In the formula (F), R ^{f1 is} a single bond, a fluoroalkylene group or a fluoroalkylene group having at least two carbon atoms with an ether oxygen atom between carbon-carbon atoms, Z ¹ is NR ¹ NR ² H, NR ³ OR ⁴ or OR ⁵ , and R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group.)
2. [2] The electric wire according to [1], wherein the fluorinated polymer contains at least one of the functional groups represented by the formula (F) in a unit represented by the following formula (U1):
   
   (In the formula (U1), each of X ¹ and X ² is independently a hydrogen atom or a fluorine atom, Q ¹ is a single bond or an ether oxygen atom, R ^f1 is a single bond, a fluoroalkylene group or a fluoroalkylene group having at least two carbon atoms with an ether oxygen atom between carbon Carbon atoms, Z ¹ is NR ¹ NR ² H, NR ³ OR ⁴ or OR ⁵ , and R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group.)
3. [3] The electric wire according to [2], wherein the fluorinated polymer contains at least three units represented by the formula (U1).
4. [4] The electric wire according to [1], wherein the fluorinated polymer contains at least three groups represented by the following formula (F1): - (R ^f2 O) _k -R ^f1 COZ ¹ (F1) (in the formula (F1), R ^{f2 is} a C _1-4 perfluoroalkylene group; k is an integer of 1 to 200; R ^f1 is a single bond, a fluoroalkylene group or a fluoroalkylene group having at least two carbon atoms with an ether oxygen atom between carbon-carbon Z ¹ is NR ¹ NR ² H, NR ³ OR ⁴ or OR ⁵ , and R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group.)
5. [5] An electric wire according to [4], wherein the fluorinated polymer is a compound in which three or four groups represented by the formula (F1) are bonded to a carbon atom.
6. [6] The electric wire according to any one of [1] to [5], wherein the amount of fluorine atoms contained in the fluorinated polymer is from 50 to 76% by mass.
7. [7] The electric wire according to any one of [1] to [6], wherein the conductor wire is made of a copper conductor or an aluminum conductor.
8. [8] The method of manufacturing the electric wire according to any one of [1] to [7], characterized by covering the outer circumference of the conductor wire with the curable composition to form a precoat layer of the cap layer, and applying heat and / or irradiation of active energy rays the precursor layer to provide a cover layer made of a cured product of the curable composition.
9. [9] A method of manufacturing the electric wire according to [8], wherein the precursor layer is formed by applying a coating composition comprising the curable composition and a liquid having a boiling point of at most 250 ° C to the outer circumference of the conductor wire and volatilizing the liquid of the applied coating composition is formed.
10. [10] A coil formed by forming the electric wire according to any one of [1] to [7] into a coil shape.

ADVANTAGEOUS EFFECTS OF THE INVENTION

According to the present invention, an electric wire and a coil can be provided which are covered with a cured product of a thermosetting or photocurable fluorinated polymer and have very good insulating properties and high productivity.

Further, according to the present invention, there can be provided a method of manufacturing an electric wire with which it is possible to manufacture an electrical wire having very good insulating properties by a simple device.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described. However, the present invention should not be construed as being limited to the following description.

[Meaning of terms in this description]

A compound represented by the formula (a) may sometimes be referred to as compound (a). Compounds represented by other formulas may also be referred to in the same way. A unit represented by the formula (b) may sometimes be referred to as unit (b). Units represented by other formulas may also be referred to in the same way. A group represented by formula (c) may be referred to as group (c). Groups represented by other formulas may also be referred to in the same way.

A "moiety" in a polymer is a radical derived from a monomer formed by the polymerization of the monomer. A unit derived from a monomer may also be referred to simply as a monomer unit. For example, a unit derived from a fluoroethylene may be referred to as a "fluoroethylene unit".

A "fluoroethylene" means a compound in which from 0 to 3 fluorine atoms in tetrafluoroethylene (CF ₂ = CF ₂ ) are replaced by (a) hydrogen atom (s) or a halogen atom (s) other than fluorine ( for example, chlorine, bromine or iodine) are substituted.

A group with a carbon chain, e.g. An alkyl group, a fluoroalkyl group, a fluoroalkylene group, a fluoroalkoxy group or a fluoroalkenyl group may be straight-chain or branched.

A "fluoroalkyl group" means a group in which at least one of the hydrogen atoms in an alkyl group is substituted by a fluorine atom. The proportion of fluorine atoms in a fluoroalkyl group is preferably at least 50%, more preferably 100%, that is, a perfluoroalkyl group when substituted by (number of fluorine atoms in the fluoroalkyl group) / (number of hydrogen atoms in an alkyl group having the same number of carbon atoms as that Fluoroalkyl group) x 100 (%) is expressed. The same is true for a fluoroalkylene group, a fluoroalkoxy group and a fluoroalkenyl group, and a perfluoroalkylene group, a perfluoroalkoxy group and a perfluoroalkenyl group are particularly preferable.

"Curing" means curing by means of crosslinking unless otherwise specified.

A "precursor layer" means a layer for forming a capping layer upon curing, and as used herein refers to a layer of a curable composition.

In this specification, "to" which represents a numerical range includes an upper limit and a lower limit.

[Electric wire]

The electric wire of the present invention comprises a conductor wire and a cover layer covering the outer periphery of the conductor wire, the cover layer being made of a cured product of a curable composition comprising a fluorinated polymer (hereinafter also referred to as fluorinated polymer (A)) which contains at least three functional groups represented by the following formula (F): -R ^f1 COZ ¹ (F) (In the formula (F), R ^{f1 is} a single bond, a fluoroalkylene group or a fluoroalkylene group having at least two carbon atoms with an ether oxygen atom between carbon-carbon atoms, Z ¹ is NR ¹ NR ² H, NR ³ OR ⁴ or OR ⁵ , and R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group.).

(Conductor wire)

As a conductor wire (also referred to as a "core wire"), a conductor wire used for an electric wire can be generally used without any special limitation. As a constituent material of the conductor wire, a copper conductor, an aluminum conductor, etc. may be mentioned. Here, a copper conductor stands for a conductor in which copper is the main component, and oxygen-free copper, low-oxygen copper or the like is mainly used. The same applies to an aluminum conductor. Further, the conductor is not limited thereto, and for example, a conductor may be used in which metal plating of e.g. Nickel, chrome, silver or tin is applied to the outer circumference of a copper wire.

The largest diameter in a cross section orthogonal to the longitudinal direction of the conductor wire is preferably from 0.002 to 20 mm. The cross-sectional shape orthogonal to the longitudinal direction of the conductor wire may be a round shape, a foil shape, or a polygonal shape such as a polygon. a quadrangular shape, his. In the case of a polygonal shape, a shape having a predetermined curvature in which corner portions are not sharp is also included.

The conductor wire (core wire) may be used as a single wire composed of a single conductor, or it may be used as a twisted wire composed of a plurality of combined conductors.

(Cover layer)

The cover layer covering the outer circumference of the conductor wire is made of a cured product of a curable composition containing a fluorinated polymer (A). The expression "has a cover layer covering the outer circumference of the conductor wire" means that the cover layer is formed along the outer circumference of the conductor wire in any cross section orthogonal to the longitudinal direction of the conductor wire. In the electric wire of the present invention, another covering layer may be provided between the conductor wire and the covering layer or on the outside of the covering layer. The thickness of the cap layer is adjusted in a suitable manner according to the purpose or type of the electric wire. The cover layer has e.g. preferably a thickness of 1 to 1000 microns, and more preferably has a thickness of 10 to 1000 microns.

The curable composition is a composition containing a fluorinated polymer (A) as a curable component and does not contain a volatile component, e.g. a solvent.

The crosslinking reaction of the fluorinated polymer (A) proceeds on the basis of the groups (F).

When Z ¹ in the groups (F) is OR ⁵ , it is considered that by the De-COZ ¹ reaction by irradiation with active energy rays -R ^f1 - radicals are generated from the groups (F) and the -R ^f1 - Radicals are bound by a coupling.

When Z ¹ is NR ¹ NR ² H, it is assumed that the groups (F) are coupled to each other, so that crosslinked sites are formed with a Diacylhydrazin- or tetrazine structure by irradiation with active energy rays and / or heating.

When Z ¹ NR ³ OR ⁴ , it is considered that -R ^f1 radicals are formed from the groups (F) by the De-COZ ¹ reaction by irradiation with active energy rays and / or heating, and -R ^f1 radicals Be tied.

When the groups (F) include both a group in which Z ¹ NR ¹ NR ² H and a group in which Z ^{1 is} OR ⁵ , it is considered that both groups react with each other by heating as it is shown by the following formula: -R ^f1 CONR ¹ NR ² H + -R ^f1 COOR ⁵ → -R ^f1 CONHNHCOR ^f1 -

In any of the above-mentioned crosslinking reactions, it is preferable to conduct the reaction under predetermined conditions, e.g. in the presence of an inert gas, e.g. Nitrogen.

The curable composition may consist only of the fluorinated polymer (A) or may contain a reactive component (hereinafter referred to as "further reactive component") other than the fluorinated polymer (A) within a range including the aforementioned crosslinking reaction of the fluorinated polymer (A) does not inhibit. The further reactive component may be a fluorinated polymer having one or two groups (F), a silane coupling agent for improving adhesion, e.g. on a conductor wire, etc. The curable composition may further comprise a non-reactive component. Hereinafter, each component contained in the curable composition will be described.

(Fluorinated polymer (A))

The fluorinated polymer (A) contains at least three groups (F) per molecule: -R ^f1 COZ ¹ (F) (In the formula (F), R ^{f1 is} a single bond, a fluoroalkylene group or a fluoroalkylene group having at least two carbon atoms with an ether oxygen atom between carbon-carbon atoms, Z ¹ is NR ¹ NR ² H, NR ³ OR ⁴ or OR ⁵ , and R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group.).

When R ^f1 in a group (F) is a fluoroalkylene group, the number of carbon atoms is preferably from 1 to 6, more preferably from 1 to 4. When the number of carbon atoms is at least 3, a linear chain structure is excellent in terms of heat stability prefers. The fluoroalkylene group is preferably a perfluoroalkylene group from the viewpoint of excellent heat stability. That is, as R ^f1 is a C _1-6 perfluoroalkylene group and preferably a C _1-4 perfluoroalkylene group is particularly preferred.

When R ^{f1 is} a fluoroalkylene group having at least two carbon atoms having an ether oxygen atom between carbon-carbon atoms, the number of carbon atoms is preferably from 2 to 10, more preferably from 2 to 6. When the number of carbon atoms is at least 3, a linear one Chain structure is preferred for excellent heat stability. The fluoroalkylene group is preferably a perfluoroalkylene group from the viewpoint of excellent heat stability. That is, as R ^f1 , a C _2-10 perfluoroalkylene group having an ether oxygen atom between carbon carbon atoms is preferable, and a C _2-6 perfluoroalkylene group having an ether oxygen atom between carbon-carbon atoms is particularly preferable.

As R ^f1 in particular CF ₂ (CF _{2) 2} (CF _{2) 3} (CF _{2) 4} CF ₂ CF (CF ₃₎ O (CF _{2) 2} CF ₂ CF (CF ₃₎ O (CF ₂ ) ₃ , (CF ₂ ) ₃ O (CF ₂ ) ₂ , (CF ₂ ) ₂ O (CF ₂ ) ₂ , CF ₂ OCF (CF ₃ ), CF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) , etc., preferred.

R ¹ , R ² , R ³ and R ⁴ are each independently preferably a hydrogen atom or a C _1-6 alkyl group, more preferably a hydrogen atom or a C ₁ or ₂ alkyl group, still more preferably a methyl group or a hydrogen atom, more preferably a hydrogen atom, in view of very good hydrogen bonding properties and excellent solubility of the fluorinated polymer (A) in an alcohol.

R ⁵ is preferably a C _1-6 alkyl group, more preferably a C _{1 or} C ₂ alkyl group, more preferably a methyl group, in view of the fluorinated polymer (A) being excellent Will have fluidity when it is heated. In view of high transparency of the cured product of the curable composition containing the fluorinated polymer (A), R ^{5 is} preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom.

As -COZ ¹ , especially -COOH, -COOCH ₃ , -COOC ₂ H ₅ , -CONHNH ₂ , -CO-N (CH ₃ ) NHCH ₃ , -CONHOH, -CONHOCH ₃ , etc., are preferred.

The number of groups (F) in the fluorinated polymer (A) is at least 3, preferably from 3 to 100, more preferably from 3 to 30. The kinds of the groups (F) may be different or identical. The combination of the groups (F) may be appropriately selected according to the kind of the above-mentioned crosslinking reaction.

When Z ¹ in a group (F) is NR ¹ NR ² H or NR ³ OR ⁴ , there is an advantage that the fluorinated polymer (A) is dissolved in an alcohol even if the fluorine atom content is high as in a perfluoropolymer ,

As the alcohol, there may be mentioned methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, methoxyethanol, methoxypropanol, etc., and methanol and ethanol are preferable.

When the fluorinated polymer (A) needs to have solubility in an alcohol, a fluorinated polymer (A) containing a solution amount of e.g. at least 2 mass% based on the total amount of the alcohol (preferably methanol) and the fluorinated polymer (A) at room temperature (25 ° C) can be obtained by adjusting the species and the ratio of the groups (F) in the fluorinated polymer (A). The solution amount of the fluorinated polymer (A) to the total amount of the alcohol and the fluorinated polymer (A) is preferably at least 3 mass%, more preferably at least 4 mass%, still more preferably at least 5 mass%.

The content of fluorine atoms in the fluorinated polymer (A) is preferably from 50 to 76% by mass. A fluorine atom content of at least 50 mass% is preferable in view of that the insulating properties and the flame retardancy will be excellent, and that of at most 76 mass% is preferable in view of that the moldability will be excellent. The content of fluorine atoms is more preferably from 55 to 65 mass%. The content of fluorine atoms can be calculated by a ¹⁹ F-NMR measurement.

The fluorinated polymer (A) may have groups (F) in side chains of the polymerized units or at the main chain ends of the polymer molecule as long as the total number of the groups (F) is at least three. When having groups (F) in side chains of polymerized units, each group (F) preferably has a structure such that it is bonded to the main chain of the polymer through a single bond or an ether oxygen atom.

(in der Formel (U1) sind X¹ und X² jeweils unabhängig ein Wasserstoffatom oder ein Fluoratom und Q¹ ist eine Einfachbindung oder ein Ethersauerstoffatom; und -R^f1COZ¹ entspricht einer Gruppe (F).)A polymerized unit having a group (F) in its side chain is a unit represented by the following formula (U1):

(In the formula (U1), each of X ¹ and X ² is independently a hydrogen atom or a fluorine atom, and Q ¹ is a single bond or an ether oxygen atom, and -R ^f1 COZ ¹ corresponds to a group (F).

Further, when a group (F) exists at a main chain end, the group (F) is preferably a group represented by the following formula (F1), a group represented by the following Formula (F11), a group represented by the following formula (F12), or the like. Further, optionally, a group (F1), a group (F11), a group (F12) or the like may be present in a side chain of a polymerized unit. - (R ^f2 O) _k -R ^f1 COZ ¹ (F1) (in the formula (F1), R ^{f2 is} a C _1-4 perfluoroalkylene group, k is an integer of 1 to 200, and -R ^f1 COZ ¹ corresponds to a group (F)). -CF ₂ COZ ¹ (F11) -CF ₂ CF ₂ COZ ¹ (F12)

(The types and examples of Z ¹ in the formulas (F11) and (F12) are the same as those described above for the group (F)).

The fluorinated polymer (A) may be e.g. a fluorinated polymer (A) with a total of at least three of the units (U1) and groups (F1). In particular, a fluorinated polymer (A) having two groups (F1) at the main chain ends and having one or more units (U1), a fluorinated polymer (A) having one group (F1) at one main chain end and two or more units (U1 ) or the like. Further, in the above, the fluorinated polymer (A) may be a fluorinated polymer having a group (F11), a group (F12) or the like instead of the group (F1) as a group (F) at the main chain end.

As the fluorinated polymer (A), a fluorinated polymer having at least three units (U1) (hereinafter also referred to as fluorinated polymer (A1)), a fluorinated polymer having at least three groups (F1) (hereinafter also referred to as fluorinated polymer (A2) ), etc., be preferred.

<Fluorinated polymer (A1)>

The fluorinated polymer (A1) may consist only of units (U1) or may consist of units (U1) and units other than units (U1). Hereinafter, each unit constituting the fluorinated polymer (A1) will be described.

In one unit (U1), Q ^{1 is} preferably an ether oxygen atom. X ¹ and X ² are preferably both fluorine atoms or hydrogen atoms, more preferably both are fluorine atoms.

Specific examples of the unit (U1) include the following units. - [CF ₂ -CF (COZ ¹ )] -, - [CF ₂ -CF (CF ₂ -COZ ¹ )] -, [CF ₂ -CF ((CF ₂ ) ₂ -COZ ¹ )] -, - [CF ₂ -CF (O (CF ₂ ) ₂ -COZ ¹ )] -, - [CF ₂ -CF (O (CF ₂ ) ₃ -COZ ¹ )] -, - [CF ₂ -CF (O (CF ₂ ) ₄ -COZ ¹ )] -, [CF ₂ -CF (OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ -COZ ¹ )] -, [CF ₂ -CF (OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₃ -COZ ¹ )] -, - [CF ₂ -CF (O (CF ₂ ) ₃ O (CF ₂ ) ₂ -COZ ¹ )] -, - [CF ₂ -CF (O (CF ₂ ) ₂ O (CF ₂ ) ₂ -COZ ¹ )] -, - [CH ₂ -CF (CF ₂ OCF (CF ₃ ) -COZ ¹ )] -, - [CH ₂ -CF (CF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) -COZ ¹ )] -. (Z ¹ is -OH, -OCH ₃ , -NHNH ₂ , -N (CH ₃ ) NHCH ₃ , -NHOH or -NHOCH _3. )

For ease of availability, the moiety (U1) is particularly preferred - [CF ₂ -CF (COOCH ₃ )] -, - [CF ₂ -CF (CF ₂ -COOCH ₃ )] -, - [CF ₂ -CF (O ( CF ₂ ) ₃ COOCH ₃ )] -, - [CF ₂ -CF (OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₃ COOCH ₃ )] -, - [CF ₂ -CF (O (CF ₂ ) ₃ CONHNH ₂ )] - or - [CF ₂ -CF (O (CF ₂ ) ₃ CONHOH)] -.

The fluorinated polymer (A1) may contain one kind of units (U1) alone or two or more kinds of units (U1) in a combination as long as it has at least three groups (F). From the viewpoint that the hydrogen bonding properties are better and the adhesion of the conductor wire is excellent, as the fluorinated polymer (A1), a fluorinated polymer containing units (U1) in which Z ^{1 is} NR ¹ NR ² H is preferable. The crosslinking conditions, the nature of Z ¹ and the solubility of the fluorinated polymer (A1) in an alcohol are the same as those described above for the fluorinated polymer (A).

Units (U1) in which Z ^{1 is} OR ⁵ can be formed by polymerizing a compound represented by the following formula (11) as a monomer. Units (U1) in which Z ^{1 is} NR ¹ NR ² H and NR ³ OR ⁴ may be formed by the later-described production process of the fluorinated polymer (A1). CX ¹ X ² = CF-Q ¹ -R ^{f 1} -COOR ⁵ (11) (in formula (11), X ¹ , X ² , Q ¹ , R ^f1 and OR ^{5 are} as defined in the formula (U1), and their examples and preferred ranges are also the same.)

(in den Formeln (U1a), (U1b) und (U1c) sind X¹, X², Q¹, R^f1, R¹, R², R³, R⁴ und R⁵ derart, wie sie in der Formel (U1) festgelegt sind, und deren Beispiele und bevorzugten Bereiche sind ebenfalls dieselben.).Hereinafter, as shown in the following formulas (U1a), (U1b) and (U1c), a unit (U1) in which Z ^{1 is} OR ⁵ is referred to as a unit (U1a), a unit (U1), wherein Z ^{1 is} NR ¹ NR ² H, is referred to as a unit (U1b), and a unit (U1) in which Z ^{1 is} NR ³ OR ⁴ is referred to as a unit (U1c).

(in the formulas (U1a), (U1b) and (U1c) X ¹ , X ² , Q ¹ , R ^f1 , R ¹ , R ² , R ³ , R ⁴ and R ^{5 are} as defined in the formula ( U1), and their examples and preferred ranges are also the same.).

The fluorinated polymer (A1) may further include fluoroethylene units (hereinafter also referred to as "units (U2)"), units represented by the later-described formula (U3) (hereinafter also referred to as "units (U3)") and further units (hereinafter also referred to as "units (U4)").

<Units (U2)>

Specific examples of the units (U2) include units derived from tetrafluoroethylene (CF ₂ = CF ₂ ) (TFE), trifluoroethylene (CF ₂ = CHF) (TrFE), chlorotrifluoroethylene (CFCl = CF ₂ ), vinylidene fluoride (CF ₂ = CH ₂ ), etc., are derived. From the viewpoint of excellent light resistance, TFE units, TrFE units and chlorotrifluoroethylene units are preferable. TFE units are particularly preferred in view of excellent adhesion to the substrate since there is a tendency for strongly polar -COZ ¹ groups to be present at the interface. TrFE units and chlorotrifluoroethylene units are particularly preferred in view of the fact that the crystallinity of the fluorinated polymer is not as high as that of TFE. Units, it is less likely that light scattering occurs and the transparency is high. TrFE units are particularly preferred in view of excellent solubility in an alcohol.

An example may include one kind of units (U2) alone or two or more kinds of units (U2) in combination.

<Units (U3)>

The unit (U3) is a unit represented by the following formula (U3) (but excluding a fluoroethylene unit). - [CX ³ X ⁴ -CY ¹ Y ² ] - (U3) (In the formula (U3), each of X ³ and X ⁴ is independently a hydrogen atom, a fluorine atom or a chlorine atom, Y ¹ is a hydrogen atom, a fluorine atom or a chlorine atom, and Y ² is a hydrogen atom, a fluoroalkyl group, a fluoroalkyl group having at least two Carbon atoms having an ether oxygen atom between carbon-carbon atoms, a fluoroalkoxy group, a fluoroalkoxy group having at least two carbon atoms having an ether oxygen atom between carbon-carbon atoms, a fluoroalkenyl group or a fluoroalkenyl group having at least two carbon atoms with an ether oxygen atom between carbon-carbon atoms.) ,

In the fluoroalkyl group in Y ² , the number of carbon atoms is preferably from 1 to 15, more preferably from 1 to 6. In view of excellent heat stability, a perfluoroalkyl group is preferred; a C _1-6 perfluoroalkyl group is more preferred; and -CF ₃ is particularly preferred. As a fluoroalkyl group having at least two carbon atoms having an ether carbon atom between carbon-carbon atoms in Y ² , the number of carbon atoms is preferably from 2 to 15, more preferably from 2 to 6. In view of excellent heat stability, a perfluoroalkyl group having at least two carbon atoms is an ether oxygen atom between carbon-carbon atoms is preferred; a C _2-6 perfluoroalkyl group having an ether oxygen atom between carbon-carbon atoms is particularly preferred.

In the fluoroalkoxy group in Y ² , the number of carbon atoms is preferably from 1 to 15, more preferably from 1 to 6. In view of excellent heat stability, a C _1-6 perfluoroalkoxy group is preferable and -OCF ₃ , -OC-F ₂ CF. ₃ , -O (CF ₂ ) ₂ CF ₃ or -O (CF ₂ ) ₃ CF ₃ is particularly preferred. In the fluoroalkoxy group having at least two carbon atoms having an ether oxygen atom between carbon-carbon atoms in Y ² , the number of carbon atoms is preferably from 2 to 15, more preferably from 2 to 6. In view of excellent heat stability, a perfluoroalkoxy group having at least two carbon atoms with an ether oxygen atom between carbon-carbon atoms is preferred and a C _2-6 perfluoroalkoxy group having an ether oxygen atom between carbon-carbon atoms is particularly preferred.

In the fluoroalkenyl group in Y ² , the number of carbon atoms is in view of that cyclization within the molecules does not proceed and the synthesis is easy, preferably from 5 to 15. In view of excellent heat stability, a perfluoroalkenyl group is preferable and - (CF _{2 4} CF = CF ₂ , - (CF ₂ ) ₅ CF = CF ₂ or - (CF ₂ ) ₆ CF = CF ₂ is particularly preferred. In the fluoroalkenyl group having at least two carbon atoms having an ether oxygen atom between carbon-carbon atoms in Y ² , the number of carbon atoms is preferably from 2 to 15, more preferably from 2 to 6. In view of excellent heat stability, a perfluoroalkenyl group having at least two carbon atoms with an ether oxygen atom between carbon-carbon atoms is preferred and a C _2-6 perfluoroalkenyl group having an ether oxygen atom between carbon-carbon atoms is particularly preferred.

As specific examples of the unit (U3), the following units may be mentioned. - [CH ₂ -CH ₂ ] -, - [CF ₂ -CF (CF ₃ )] -, - [CH ₂ -CF (CF ₃ )] -, - [CH ₂ -CH (CF ₃ )] -, - [CH ₂ -CF ((CF ₂ ) ₃ CF ₃ )] -, - [CH ₂ -CF ((CF ₂ ) ₅ CF ₃ )] -, - [CF ₂ -CF (OCF ₃ )] -, - [ CF ₂ -CF (OCF ₂ CF ₃ )] -, - [CF ₂ -CF (O (CF ₂ ) ₂ CF ₃ )] -, - [CF ₂ -CF (O (CF ₂ ) ₃ CF ₃ )] - , - [CF ₂ -CF (OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ CF ₃ )] -, - [CF ₂ -CF ((CF ₂ ) ₄ CF = CF ₂ )] -, - [CF ₂ -CF ((CF ₂ ) ₅ CF = CF ₂ )] -, - [CF ₂ -CF ((CF ₂ ) ₆ CF = CF ₂ )] -.

The moiety (U3) is preferably - [CH ₂ -CH _2] -, - [CF ₂ -CF (CF ₃ )] -, - [CF ₂ -CF (OCF ₃ )] -, - [CF ₂ -CF ( O (CF ₂ ) ₂ CF ₃ ] - or - [CF ₂ -CF (OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ CF ₃ ] - because the fluorinated polymer (A1) will have a low glass transition temperature, a excellent fluidity and excellent Will have moldability, and at the time of curing it by at least one of heating and irradiating with active energy rays, the mobility will be high and the crosslinking reaction between molecules tends to proceed rapidly.

The fluorinated polymer may have one kind of units (U3) alone or two or more kinds of units (U3) in combination.

The units (U3) can be formed by polymerizing a compound (31) as a monomer. CX ³ X ⁴ = CY ¹ Y ² (31) (In the formula (31), X ³ , X ⁴ , Y ¹ and Y ² are as defined in the formula (U3), and their examples and preferred ranges are also the same.)

The units (U4) may be units which are e.g. of propylene, isobutene, 2-trifluoromethyl-3,3,3-trifluoro-1-propene, etc. are derived.

(Preferred Embodiments of the Fluorinated Polymer (A1))

The number of the groups (F) in the fluorinated polymer (A1) is preferably at least three in view of excellent crosslinking reactivity of the groups (F), and should be better small if the molecular weight of the fluorinated polymer (A1) is large and should be better be large when the molecular weight of the fluorinated polymer (A1) is small. Usually, 3 to 100 is preferred, and from 3 to 30 is more preferred. Here, the number of groups (F) in the fluorinated polymer (A1) is an average number per molecule. The number of groups (F) having the fluorinated polymer (A1) (in the case where no group (F) is present at the main chain ends) corresponds to the number of units (U1) containing the fluorinated polymer (A1). having. Z ¹ in the groups (F) of the fluorinated polymer (A1) is preferably composed of a single kind of groups or composed of two kinds of NR ¹ NR ² H and OR ⁵ . That is, the units (U1) in the fluorinated polymer (A1) are preferably composed of one kind of unit (U1a), unit (U1b) or unit (U1c) or two types of unit (U1a) and unit (U1b ).

When the units (U1) in the fluorinated polymer (A1) are composed of two kinds of the unit (U1a) and the unit (U1b), the unit (U1b) preferably makes from 1 to 90 mol%, more preferably from 5 to 70 mol%, particularly preferably from 10 to 60 mol% based on the total amount of the unit (U1a) and the unit (U1b), taking into consideration the solubility of the fluorinated polymer (A1) in an alcohol, suppressing one Foaming during curing, the crosslink density of the available cured product, etc.

The weight average molecular weight of the fluorinated polymer (A1) is preferably 1,000 to 1,000,000. More preferably, the weight average molecular weight is at least 3,000, since the volatile components will be less. The weight average molecular weight is more preferably at most 100,000, since it will then have excellent solubility. When the weight average molecular weight of the fluorinated polymer (A1) is from 1,000 to 15,000, the viscosity is from 1 to 1,000 Pa · s, and by heating at 25 to 100 ° C, the viscosity will be at most 10 Pa · s, thereby providing a curing agent composition containing the fluorinated polymer (A1) can be applied to a conductor wire without the use of a solvent. The fluorine atom content in the fluorinated polymer (A1) is identical to that described for the fluorinated polymer (A).

The weight-average molecular weight can be obtained as the molecular weight calculated as PMMA (polymethyl methacrylate) by gel permeation chromatography (GPC). In this specification, the weight average molecular weight is a weight average obtained by the above-mentioned method unless otherwise specified.

The viscosity can be obtained by a rotary viscometer at 25 ° C. In this specification, the viscosity is a viscosity obtained by the above-mentioned method unless otherwise specified.

The content of units (U1) in the fluorinated polymer (A1) is preferably from 0.02 to 7.1 mmol / g, more preferably from 0.1 to 4 mmol / g, more preferably from 0.1 to 3 mmol / g, more preferably from 0.2 to 1 mmol / g, based on the mass of the fluorinated polymer (A1), in view of the solubility of the fluorinated polymer (A1) in an alcohol, the suppression of foaming during curing, the crosslinking density of the obtainable cured product, etc.

When the units (U1) consist only of units (U1b) in which Z ¹ NR ¹ NR ² H, the content of units (U1b) relative to the mass of the fluorinated polymer (A1) is preferably from 0.02 to 4 mmol / g, more preferably from 0.02 to 1 mmol / g, particularly preferably from 0.2 to 0.5 mmol / g, in view of the solubility of the fluorinated polymer (A1) in an alcohol, the suppression of Foaming during curing, the crosslink density of the available cured product, etc.

When the units (U1) consist only of units (U1c) in which Z ^{1 is} NR ³ OR ⁴ , the content of units (U1c) based on the mass of the fluorinated polymer (A1) is preferably from 0.1 to 4 mmol / g, more preferably from 0.2 to 3 mmol / g, particularly preferably from 0.3 to 1 mmol / g, in view of the solubility of the fluorinated polymer (A1) in an alcohol, the suppression of foaming during the Curing, the crosslink density of the available cured product, etc.

When the units (U1) consist only of units (U1a) in which Z ^{1 is} OR ⁵ , the content of units (U1a) based on the mass of the fluorinated polymer (A1) is preferably from 0.1 to 4 mmol / g more preferably from 0.1 to 3 mmol / g, more preferably from 0.3 to 1 mmol / g, in view of suppressing foaming during curing, crosslinking density of the available cured product, etc.

The contents of the units (U1a) to the units (U1c) in the fluorinated polymer (A1) can be calculated by means of ¹⁹ F-NMR measurements.

The proportion of units (U1) in all units of the fluorinated polymer (A1) is preferably from 1 to 100 mol%, more preferably from 3 to 98 mol%, still more preferably from 3 to 50 mol%, particularly preferably from 5 to 15 mol%, in view of the solubility of the fluorinated polymer (A1) in an alcohol, the suppression of foaming during curing, the crosslinking density of the available cured product, etc.

A preferred embodiment of the fluorinated polymer (A1) is a fluorinated polymer comprising units (U1), units (U2) and units (U3), wherein in all units of the fluorinated polymer (A1) the proportion of units (U1) of 1 to 98 mol%, the proportion of units (U2) is from 1 to 95 mol%, and the proportion of units (U3) is from 1 to 95 mol%.

The contents of the units (U1) to the units (U4) in the fluorinated polymer (A1) can be calculated by means of ¹⁹ F-NMR and ¹ H-NMR measurements.

[Process for Producing Fluorinated Polymer (A1)]

For example, when the units (U1) consist of only the units (U1a), a fluorinated polymer (A1) is obtained by polymerizing a monomer (11) and optional monomers such as fluoroethylene, a monomer (31), etc. Known method (eg, the method described in WO 2015/098773 disclosed) by using the same such that the units (U1a), the units (U2), the units (U3), etc., derived from the respective monomers are in the desired proportions in the available fluorinated Polymer (A1) are present.

As the polymerization method, a known polymerization method, such as e.g. a suspension polymerization, a solution polymerization, an emulsion polymerization or a bulk polymerization. Solution polymerization is preferred in that it is simple to control the molecular weight, e.g. the weight average molecular weight to be adjusted to a given degree. As a solvent for solution polymerization, a fluorinated solvent as described later is preferable.

A fluorinated polymer (A1) in which the units (U1) consist of the units (U1a) and the units (U1b) or the units (U1) consist only of the units (U1b) can be prepared, for example, by a method in which the fluorinated polymer (A1) containing units (U1a) obtained as described above and a hydrazine compound represented by the following Formula (5) (hereinafter also referred to simply as "hydrazine compound"), so that some or all of the units (U1a) are modified into units (U1b). HR ¹ N-NR ² H (5) (in the formula (5), R ¹ and R ^{2 are} as defined in the formula (U1), and their examples and preferred ranges are also the same.)

The hydrazine compound may be hydrazine, methylhydrazine or 1,2-dimethylhydrazine. The hydrazine compound may be in the form of a hydrate, e.g. Hydrazine monohydrate. Hereinafter, "hydrazine compound" is used as a term which includes a hydrate of a hydrazine compound. As the hydrazine compound, hydrazine monohydrate is preferable in view of the safety and solubility of the obtainable fluorinated polymer (A1) in an alcohol. The hydrazine compound to be subjected to the reaction may be in the form of an aqueous solution or a salt. An aqueous solution is more preferable. As the hydrazine compound, a commercial product can be used.

The proportion of the modification of the units (U1a) to the units (U1b) can be determined by the amount of the hydrazine compound used for the units (U1a) in the fluorinated polymer (A1) containing the units (U1a) as the starting material can be used. In the obtainable fluorinated polymer (A1), the content of units in which Z ^{1 is} NR ¹ NR ² H can be measured by quantifying the residual -COOR ⁵ groups by infrared spectroscopy (IR).

In particular, the amount of the hydrazine compound to be used is preferably from 0.1 to 20 mol, more preferably from 0.3 to 15 mol, more preferably from 0.5 to 10 mol, based on 1 mol of the groups represented by -COOR ^{5 can be represented} in the fluorinated polymer (A1) containing the units (U1a) although not particularly limited, as long as a fluorinated polymer (A1) having the desired proportion of the units (U1a) belonging to the units ( U1b) are modified is available. In this case, it is to cause all of the units (U1a) can be modified to the units (U1b), preferably using 3 to 20 moles of the hydrazine compound per mol of the groups represented by -COOR ^5.

The reaction may be carried out in the presence of a solvent. As the solvent, preferred is a solvent which can dissolve starting material components (a fluorinated polymer (A1) containing the units (U1a), a hydrazine compound). A solvent in which at least one fluorinated polymer (A1) containing the units (U1a) is soluble is preferred. As the solvent, there may be mentioned a fluorinated solvent, an ether type solvent or an ester type solvent, and the solvent may be selected in a suitable manner according to the polarity of the raw material components, etc. As the solvent, one kind may be used alone or two or more kinds may be used in combination. Further, it is also preferable to use such a solvent and an alcohol as a mixture. It is also possible to add an alcohol as the reaction progresses. Here, as the alcohol, an alcohol described in the section for the fluorinated polymer (A) may be used.

The fluorinated solvent contains fluorine and carbon and may further contain chlorine, oxygen and hydrogen. For example, a fluorinated alkane, a fluorinated aromatic compound, a fluoroalkyl ether, a fluorinated alkylamine, a fluoroalcohol, etc. may be mentioned.

As the fluorinated alkane, a compound having 4 to 8 carbon atoms is preferable. Commercially available products may be exemplified by CF ₃ CH ₂ CF ₂ H (HFC-245fa), CF ₃ CH ₂ CF ₂ CH ₃ (HFC-365mfc), perfluorohexane, 1H-perfluorohexane, perfluorooctane, C ₆ F ₁₃ H (manufactured by Asahi Glass Co ., Ltd., Asahiklin (registered trademark) AC-2000), C ₆ F ₁₃ C ₂ H ₅ (manufactured by Asahi Glass Co., Ltd., Asahiklin (registered trademark) AC-6000), C ₂ F ₅ CHFCHFCF ₃ (manufactured by Chemers, Bartrell (registered trademark) XF), etc.

As the fluorinated aromatic compound, there can be mentioned hexafluorobenzene, trifluoromethylbenzene, perfluorotoluene, bis (trifluoromethyl) benzene, etc. As the fluoroalkyl ether, a C _4-12 compound is preferred. Commercially available products may be, for example, CF ₃ CH ₂ OCF ₂ CF ₂ H (manufactured by Asahi Glass Co., Ltd., Asahiklin (registered trademark) AE-3000), C ₄ F ₉ OCH ₃ (manufactured by 3M, Novec (registered trademark) 7100), C ₄ F ₉ OC ₂ H ₅ (manufactured by 3M, Novec (registered trademark) 7200), C ₂ F ₅ CF (OCH ₃ ) C ₃ F ₇ (manufactured by 3M, Novec (registered trademark) 7300), etc., be.

As the fluorinated alkylamine, there may be mentioned perfluorotripropylamine, perfluorotributylamine, etc. As the fluoroalcohol, there may be mentioned 2,2,3,3-tetrafluoropropanol, 2,2,2-trifluoroethanol, hexafluoroisopropanol, etc. As other examples, dichloropentafluoropropane (HCFC-225), perfluoro (2-butyltetrahydrofuran), etc. may be mentioned. Dichloropentafluoropropane is commercially available as Asahiklin (Registered Trade Mark) AK-225 series (manufactured by Asahi Glass Co., Ltd.) such as AK-225G.

As the ether type solvent, there may be mentioned ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diisopropyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, etc.

As the ester type solvent, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, etc. may be mentioned.

The reaction can be carried out, for example, by dissolving a fluorinated polymer (A1) containing units (U1a) in the above-mentioned solvent and adding a hydrazine compound at 0 to 30 ° C. After adding, the mixture is heated from 30 to 100 ° C and reacted for 1 minute to 10 hours, so that the desired fluorinated polymer (A1) containing units (U1b) is obtained.

A fluorinated polymer (A1) in which the units (U1) consist of the units (U1a) and the units (U1c) or the units (U1) consist only of the units (U1c) can be prepared, for example, by a method in which a fluorinated polymer (A1) containing units (U1a) and obtainable in the manner described above and a hydroxylamine compound represented by the following formula (6) (may be referred to simply as "hydroxylamine compound" hereinafter) ), so that some or all of the units (U1a) are modified into units (U1c). NHR ³ OR ⁴ (6) (in the formula (6), R ³ and R ^{4 are} as defined in the formula (U1), and their examples and preferred ranges are also the same.)

As the hydroxylamine compound, there may be mentioned hydroxylamine, N-methylhydroxylamine, N, O-dimethylhydroxylamine or isopropylhydroxylamine, and hydroxylamine is preferable from the viewpoint of better solubility of the obtainable fluorinated polymer (A1) in an alcohol. The hydroxylamine compound to be subjected to the reaction may be in the form of an aqueous solution or a salt. An aqueous solution is preferred in terms of safety. As the hydroxylamine compound, a commercial product can be used.

The process for producing a fluorinated polymer (A1) containing units (U1c) by reacting the fluorinated polymer (A1) containing units (U1a) and the hydroxylamine compound to modify some or all of the units (U1a) to the unit (U1c) may be, for example, the same method as the above-described method for producing the fluorinated polymer (A 1) containing the units (U1b), except that the hydrazine compound is changed to the hydroxylamine compound. Also in this case, the content of units in which Z ^{1 is} NR ³ OR ⁴ can be measured by quantifying the residual -COOR ⁵ groups by infrared spectroscopy (IR).

Further, in a case where a fluorinated polymer (A1) contains all of the units (U1a), the units (U1b) and the units (U1c), the following may be specifically mentioned as a method for producing such a fluorinated polymer (A1) ,

(a) A fluorinated polymer (A1) containing the units (U1a) and the hydrazine compound are reacted and then the hydroxylamine compound is reacted.

(b) A fluorinated polymer (A1) containing the units (U1a) and the hydroxylamine compound are reacted and then the hydrazine compound is reacted.

(c) A fluorinated polymer (A1) containing the units (U1a) and the hydroxylamine compound and the hydrazine compound are reacted.

In the above (a) to (c), however, the amounts of the hydrazine compound and the hydroxylamine compound to be used are adjusted to the proportions of the units (U1a), the units (U1b) and the units (U1c) in meet the desired fluorinated polymer (A1).

Further, in the above (a) to (c), by adjusting the amounts of the hydrazine compound and the hydroxylamine compound, a fluorinated polymer (A1) having only the units (U1b) and the units (U1c) as the units (U1) can be prepared ,

<Fluorinated polymer (A2)>

The fluorinated polymer (A2) is a fluorinated polymer having at least three groups (F1) as groups (F). - (R ^f2 O) _k -R ^f1 COZ ¹ (F1) (in the formula (F1), R ^{f2 is} a C _1-4 perfluoroalkylene group, k is an integer of 1 to 200, and -R ^f1 COZ ¹ corresponds to a group (F)).

That R ^{f2 is} a C _1-4 perfluoroalkylene group is in the group (F1), means specifically that: - (R ^{f 2} O) _k - - (C _a F _2a O) _k - (a is an integer from 1 to 4, k is an integer from 1 to 200, and the respective -C _a F _2a O units may be the same or different).

The -C _a F _2a O unit may be straight or branched and may, for example, -CF ₂ CF ₂ CF ₂ CF ₂ O-, -CF ₂ CF ₂ CF ₂ O-, -CF (CF ₃₎ CF ₂ O-, -CF ₂ CF ₂ O- or -CF ₂ O- be. k can be adjusted in a suitable manner depending on the desired molecular weight. A preferred range of k is from 2 to 100.

R ^f2 may be a combination of a plurality of units, and in such a case the respective units may be block, alternating or random.

Specifically, - (R ^f2 O) _k - - (CF ₂ CF ₂ CF ₂ CF ₂ O) _k1 - (CF ₂ CF ₂ CF ₂ O) _k2 - (CF (CF ₃₎ CF ₂ O) _k3 - (CF ₂ CF ₂ O) _k4 - (CF ₂ O) _{k 5} -, where k 1, k ₂ , k 3, k 4 and k 5 are each independently an integer of 0 or more, the sum of k 1, k 2, k 3, k 4 and k 5 of 1 is up to 200 and the respective repeating units can be present as a block, alternately or statistically.

R ^f2 is preferably {(CF ₂ O) _k11 (CF ₂ CF ₂ O) _{k 12} ), (CF ₂ CF ₂ O) _k13 or (CF ₂ CF ₂ CF ₂ O) _k14 , more preferably {(CF ₂ O) _k11 (CF ₂ CF ₂ O) _k12 } or (CF ₂ CF ₂ O) _k13 . Here, k11 is an integer of at least 1, k12 is an integer of at least 1, k11 + k12 is an integer of 2 to 200, and the bonding order of k11 CF ₂ O and k12 CF ₂ CF ₂ O is not limited. Each of k13 and k14 is an integer from 1 to 200.

Specific examples of the group (F1) include the following groups. - (CF ₂ O) _k11 (CF ₂ CF ₂ O) ₂ -CF _k12 -COZ ^1, - (CF ₂ O) _k11 (CF ₂ CF ₂ O) _{k 12} - (CF ₂ ) ₂ -COZ ¹ , - (CF ₂ O) _k11 (CF ₂ CF ₂ O) _{k 12} - (CF ₂ ) ₃ -COZ ¹ , - (CF ₂ CF ₂ O) _{k 13} -CF ₂ -COZ ¹ , - (CF ₂ CF ₂ O) _{k 13} - (CF ₂ ) ₂ -COZ ¹ , - (CF ₂ CF ₂ CF ₂ O) _k14 - (CF ₂ ) ₂ -COZ ¹ , - (CF ₂ CF ₂ CF ₂ O) _k14 - (CF ₂ ) ₃ -COZ ¹ ,

(Z ¹ is -OH, -OCH ₃ , -OC ₂ H ₅ , -NHNH ₂ , -N (CH ₃ ) NHCH ₃ , -NHOH or -NHOCH _3. k11, k12, k13 and k14 are the same as above have been specified.)

In - (CF ₂ O) _k11 (CF ₂ CF ₂ O) _{k 12} , it is preferred that k 11 is from 1 to 50, k 12 is from 3 to 149 and k 11 + k 12 is from 5 to 150, and it is more preferable that k11 is from 1 to 10, k12 is from 10 is up to 99 and k11 + k12 is from 15 to 100. In - (CF ₂ CF ₂ O) _k13 , k13 is preferably from 5 to 150, more preferably from 15 to 100. In - (CF ₂ CF ₂ CF ₂ O) _{k 14} , k14 is preferably from 5 to 150, more preferably from 15 to 100th

The fluorinated polymer (A2) may contain one kind of groups (F1) alone or two or more kinds of groups (F1) in a combination as long as it has at least three groups (F1). From the viewpoint that the hydrogen bonding properties are better and the adhesion to the conductor wire is excellent, the fluorinated polymer (A2) is preferably a fluorinated polymer containing groups (F1) in which Z ^{1 is} NR ¹ NR ² H. The crosslinking conditions, the nature of Z ¹ and the solubility of the fluorinated polymer (A2) in an alcohol are the same as those described above for the fluorinated polymer (A).

Hereinafter, as shown in the following formulas (F1a), (F1b) and (F1c), a group (F1) in which Z ^{1 is} OR ⁵ is called a group (F1a), a group (F1) wherein Z ^{1 is} NR ¹ NR ² H, is referred to as a group (F1b), and a group (F1) in which Z ^{1 is} NR ³ OR ⁴ is called a group (F1c). - (R ^f2 O) _k -R ^f1 COOR ⁵ (F1a) - (R ^f2 O) _k -R ^f1 CONR ¹ NR ² H (F1b) - (R ^f2 O) _k -R ^f1 CONR ³ OR ⁴ (F1c)

It is preferable that at least three (F1) groups containing a fluorinated polymer (A2) are preferable in view of the ease of preparation of the fluorinated polymer (A2), the uniformity of the curing reaction in the curable composition, etc. comprises, are composed of a kind of groups. Alternatively, a combination of two types of groups that react with each other is preferable. In particular, it is preferable that all the groups (F1) in the fluorinated polymer (A2) are selected from one kind of groups (F1a), groups (F1b) or groups (F1c), or a combination of two kinds of groups (F1a) and groups (F1). F1b) exist.

• F1: Eine Gruppe die durch die Formel (F1) dargestellt ist. n ist eine ganze Zahl von mindestens 3.
• Y³: Eine (n + m)-wertige, perfluorierte gesättigte Kohlenwasserstoffgruppe, eine (n + m)-wertige, perfluorierte gesättigte Kohlenwasserstoffgruppe mit einem Ethersauerstoffatom zwischen Kohlenstoff-Kohlenstoff-Atomen oder ein (n + m)-wertiges Kohlenstoffgrundgerüst, in dem ein Ethersauerstoffatom zwischen Kohlenstoff-Kohlenstoff-Atomen angeordnet sein kann, jedoch keine -OCF₂O-Struktur in einer solchen Gruppe vorliegt, n + m ist eine ganze Zahl von 3 bis 20.
• F2: Eine Gruppe, die durch die folgende Formel (F2) dargestellt ist. m ist eine ganze Zahl von 0 oder mehr. R^f3-(CF₂CF₂CF₂CF₂O)_k1-(CF₂CF₂CF₂O)_k2-(CF(CF₃)CF₂O)_k3- (F2) (in der Formel (F2) sind k1, k2 und k3 derart, wie es in den vorstehenden spezifischen Beispielen für -(R^f2O)_k- beschrieben ist; R^f3 ist eine C_1-20-Perfluoralkylgruppe, eine C_1-20-Perfluoralkoxygruppe, eine C_2-20-Perfluoralkylgruppe mit einem Ethersauerstoffatom zwischen Kohlenstoff-Kohlenstoff-Atomen (jedoch liegt in einer solchen Gruppe keine -OCF₂O-Struktur vor) oder eine C_2-20-Perfluoralkoxygruppe mit einem Ethersauerstoffatom zwischen Kohlenstoff-Kohlenstoff-Atomen (jedoch liegt in einer solchen Gruppe keine -OCF₂O-Struktur vor).

As the fluorinated polymer (A2), there may be mentioned, for example, a compound represented by the following formula (A2a). (F1) _n Y ³ (-F2) _m (A2a)

• F1: a group represented by the formula (F1). n is an integer of at least 3.
• Y ³ : an (n + m) -valent, perfluorinated saturated hydrocarbon group, an (n + m) -valent, perfluorinated saturated hydrocarbon group having an ether oxygen atom between carbon-carbon atoms or an (n + m) -valent carbon backbone, in which an ether oxygen atom may be located between carbon-carbon atoms, but no -OCF ₂ O structure is present in such a group, n + m is an integer of 3 to 20.
• F2: A group represented by the following formula (F2). m is an integer of 0 or more. R ^f3 - (CF ₂ CF ₂ CF ₂ CF ₂ O) _k1 - (CF ₂ CF ₂ CF ₂ O) _k2 - (CF (CF ₃ ) CF ₂ O) _k3 - ( _{F 2} ) (In the formula (F2), k1, k2 and k3 are as described in the above specific examples of - (R ^f2 O) _k -; R ^f3 is a C _1-20 perfluoroalkyl group, a C _1-20 Perfluoroalkoxy group, a C _2-20 perfluoroalkyl group having an ether oxygen atom between carbon-carbon atoms (however, in such group there is no -OCF ₂ O structure) or a C _2-20 perfluoroalkoxy group having an ether oxygen atom between carbon-carbon Atoms (however, there is no -OCF ₂ O structure in such a group).

The number of carbon atoms in Y ³ is preferably from 1 to 50, more preferably from 1 to 20, and more preferably from 1 to 5. As Y ^{3, there} may be mentioned, for example, groups represented by the following (a) to (g) become. The valence of Y ³ is represented by the (n + m) value and is an integer of 3 to 20. The value of (n + m) is preferably from 3 to 6.

As R ^f3 , a straight-chain structure, a branched structure, a ring structure or a structure having a partial ring structure may be cited; a straight-chain structure or a branched structure is preferable; and a straight-chain structure is particularly preferable. A perfluoroalkyl group or a perfluoroalkoxy group is preferred; and a perfluoroalkoxy group is more preferable. The number of carbon atoms in R ^f3 is more preferably from 1 to 10, more preferably from 1 to 6. Particularly, a trifluoromethoxy group, a heptafluoropropyloxy group, a tridecafluorohexyloxy group, etc. may be mentioned. For example, since the fluorinated polymer (A2a) has F 2, foaming at the time of curing can be suppressed, or the crosslinking density of the available cured product can be adjusted. The ratio of m to n + m in the fluorinated polymer (A2a) is preferably from 0 to 0.5.

In the fluorinated polymer (A2a), n indicating the number of the groups (F1) is not particularly limited as long as it is at least 3. The groups (F1) can be attached to all of the bonds of Y ³ . For example, when Y ^{3 is} a group (a), the number of groups (F1) may be 3 or 4. The fluorinated polymer (A2a) is preferably a compound in which Y ^{3 is} a group (a) and the number n of the groups (F1) is 4 in view of excellent crosslinking efficiency.

The weight average molecular weight of the fluorinated polymer (A2) is preferably 1,000 to 20,000. More preferably, the weight average molecular weight is at least 3,000, since the evaporation components will be less. The weight average molecular weight is more preferably at most 10,000, since the polymer will then have excellent solubility. When the weight-average molecular weight of the fluorinated polymer (A2) is from 1,000 to 5,000, the viscosity will be from 1 to 100 Pa · s and becomes at most 10 Pa · s when heated at 25 to 100 ° C, thereby providing a curing agent composition containing the fluorinated polymer (A1) can be applied to a conductor wire without the use of a solvent. The fluorine atom content in the fluorinated polymer (A2) is the same as that described for the fluorinated polymer (A).

[Process for Producing Fluorinated Polymer (A2)]

The fluorinated polymer (A2) can be synthesized, for example, by synthesizing Y ³ [(R ^{f 2} O) _k -R ^f1 COF] _n as a fluorinated polymer (A2a) in which the groups (F1) are the groups (F1a) known methods (for example, the method, which in the Japanese Patent No. 5,028,801 and then esterification of the same or esterification thereof followed by hydrolysis.

The fluorinated polymer (A2a) in which the groups (F1) consist of the groups (F1a) and the groups (F1b), or in which the groups (F1) consist only of the groups (F1b), can be obtained, for example, by a method are prepared by reacting a fluorinated polymer (A2a) containing the groups (F1a) obtained in the manner described above and a hydrazine compound to make some or all of the groups (F1a) into groups (F1b) to modify.

In particular, a fluorinated polymer (A2a) in which the groups (F1) consist of the groups (F1a) and the groups (F1b) or in which the groups (F1) consist only of the groups (F1b) can be obtained by a method which is similar to the method of modifying some or all of the units (U1a) of the fluorinated polymer (A1) containing the units (U1a) with a hydrazine compound to units (U1b) in the above description. However, in the fluorinated polymer (A2a), the reaction temperature is preferably in the range of 10 to 100 ° C.

The fluorinated polymer (A2a) in which the groups (F1) consist only of the groups (F1a) and the groups (F1c) or the groups (F1) consist only of the groups (F1c) can be produced, for example, by a method in which a fluorinated polymer (A2a) containing groups (F1a) obtained in the manner described above is reacted with a hydroxylamine compound to modify some or all of the groups (F1a) to groups (F1c) ,

In particular, a fluorinated polymer (A2a) in which the groups (F1) consist only of the groups (F1a) and the groups (F1c) or the groups (F1) consist of only the groups (F1c) can be prepared by a method which is similar to the method in the above description, in which some or all of the units (U1a) in the fluorinated polymer (A1) containing the units (U1a) are modified by a hydroxylamine compound to units (U1c). However, in the fluorinated polymer (A2a), the reaction temperature is preferably in the range of 10 to 100 ° C.

[Curable composition]

The cap layer in the electric wire of the present invention is composed of a cured product of a curable composition containing a fluorinated polymer (A). The curable composition may consist only of the fluorinated polymer (A). As the fluorinated polymer (A), one kind may be used alone or two or more kinds may be used in combination. When two or more kinds are to be combined, a combination of two or more kinds of the fluorinated polymer (A1), a combination of two or more kinds of the fluorinated polymer (A2), a combination of the fluorinated polymer (A1) and the fluorinated polymer (A2), etc. The content of the fluorinated polymer (A) in the curable composition is preferably from 10 to 100% by mass, more preferably from 50 to 100% by mass, based on the total amount of the curable composition.

The curable composition may contain other reactive components in addition to the fluorinated polymer (A) as long as the crosslinking reaction of the fluorinated polymer (A) is not impaired. Other reactive components may be a fluorinated polymer having one or two groups (F), a silane coupling agent for improving adhesion to a conductive wire, etc. The silane coupling agent may be, for example, a silane coupling agent which is incorporated in US Pat WO 2015/098773 is disclosed.

The content of the other reactive components in the curable composition is preferably from 0.01 to 50% by mass, more preferably from 0.1 to 10% by mass, based on the total amount of the curable composition.

The curable composition may further contain non-reactive components. The non-reactive components include an inorganic filler, a fluoropolyether compound, a perfluororesin, e.g. Polytetrafluoroethylene (manufactured by Asahi Glass Co. Ltd., Fluon (Registered Trade Mark) PTFE Fine Powder), a partially fluorinated resin, e.g. an ethylene / tetrafluoroethylene copolymer (manufactured by Asahi Glass Co. Ltd., Fluon (registered trademark) ETFE Powder), an organic pigment, etc.

As the organic filler, metal oxide particles, e.g. Silica, titania, zirconia, alumina, etc., glass fibers, carbon fibers, various inorganic pigments, etc., are preferable. The largest diameter of the inorganic filler is not particularly limited, but is preferably from 0.1 to 1000 μm, since the filler is then easily dispersed in the cap layer. The content of the inorganic filler is preferably from 20 to 200 parts by mass, more preferably from 50 to 100 parts by mass, based on 100 parts by mass of the fluorinated polymer (A). When the content of the inorganic filler is at least the lower limit in the above range, the hardness is further increased. If it is at most the upper limit in the above range, the moldability will be excellent.

The content of the non-reactive components other than the inorganic filler in the curable composition is preferably from 10 to 90% by mass, more preferably from 30 to 70% by mass, based on the total amount of the curable composition.

In the manufacture of an electrical wire, the curable composition may be used as it is to cover the outer periphery of the conductor wire to form a precursor layer formed of the curable composition. From the viewpoint of working efficiency, it is preferred to prepare a coating composition containing the curable composition and a Solvent, and to form a precursor layer using the coating composition. Then, the precursor layer is cured to obtain a cap layer, thereby producing an electric wire.

[Coating Composition]

The coating composition is a liquid composition comprising the curable composition and a solvent that dissolves or disperses the curable composition. The use of the coating composition facilitates the formation of a precursor layer on the outer circumference of the conductor wire, thereby improving productivity. When the coating composition is used, a coating film made of the coating composition is formed on the outer circumference of the conductor wire, and then the solvent is removed from the coating film, whereby a precursor layer made of the curable composition is obtainable.

As the solvent to be used for the coating composition, a solvent having a function of sufficiently dissolving or dispersing the curable composition is preferable. The solvent preferably contains a liquid having a boiling point of at most 250 ° C (hereinafter referred to as "liquid (L)") for ease of removal. As the liquid (L), an alcohol having a boiling point of at most 250 ° C and an alcohol having a boiling point of at most 250 ° C of compounds exemplified as the solvent for producing a fluorinated polymer (A) (but excluding an alcohol) are exemplified are preferred. As the solvent, one kind may be used alone or two or more kinds may be used in combination. When two or more kinds of liquid (L) having different boiling points are used, the foaming of the cured product is simply satisfactorily suppressed.

The content of the curable composition in the coating composition is preferably from 0.1 to 99% by mass, more preferably from 1 to 70% by mass, particularly preferably from 5 to 60% by mass. The content of the solvent in the coating composition is preferably from 99.9 to 1 mass%, more preferably from 99 to 30 mass%, particularly preferably from 95 to 40 mass%. The content of the liquid (L) in the solvent is preferably from 50 to 100% by mass, more preferably from 70 to 100% by mass.

[Method of Making Electric Wire]

1. (1) Der Außenumfang des Leiterdrahts wird mit einer aushärtbaren Zusammensetzung bedeckt, die ein fluoriertes Polymer enthält, das mindestens drei Gruppen (F) enthält, so dass eine Vorstufenschicht gebildet wird (nachstehend auch als „Vorstufenschicht-Bildungsschritt“ bezeichnet).
2. (2) Auf die Vorstufenschicht, die in dem vorstehenden (1) erhalten worden ist, wird Wärme angewandt und/oder werden aktive Energiestrahlen eingestrahlt, so dass eine Abdeckungsschicht erhalten wird, die aus einem ausgehärteten Produkt der vorstehend genannten aushärtbaren Zusammensetzung hergestellt ist (nachstehend auch als „Aushärtungsschritt“ bezeichnet).

The method of manufacturing an electric wire in the present invention is a method of manufacturing an electric wire including a conductor wire and a cover layer covering the outer periphery of the conductor wire, and includes the following steps (1) and (2).

1. (1) The outer periphery of the conductor wire is covered with a curable composition containing a fluorinated polymer containing at least three groups (F) to form a precursor layer (hereinafter also referred to as "precursor layer forming step").
2. (2) Heat is applied to the precursor layer obtained in the above (1) and / or active energy rays are irradiated to obtain a cap layer made of a cured product of the above curable composition (hereinafter also referred to as "curing step").

Precursor layer forming step

The method of forming the precoat layer for the cap layer on the outer circumference of the conductor wire is not particularly limited as long as it is a method of forming a uniform precursor layer on the entire outer circumference of the conductor wire. As a method which causes the curable composition to flow by heating, whereby the curable composition is applied to the outer periphery of the conductor, a molding method of extruding the curable composition to cover the outer periphery of the conductor wire therewith (electrical wire extrusion molding), etc. may be mentioned become.

The application of the curable composition is preferably carried out by applying a coating composition comprising the curable composition and a solvent, preferably a solvent containing a liquid (L). As Coating composition, the above-described coating composition can be used. The coating composition may be applied to the outer circumference of the conductor wire by the same method as the method of applying the curable composition.

As the method for applying the curable composition, a spin coating method, a wipe coating method, a spray coating method, a squeegee coating method, a dip coating method, a die coating method, an ink jet method, a flow coating method, a roll coating method, a casting method, a Langmuir-Blodgett method can be used Gravure coating, etc., to be called. In particular, a dip coating method is preferable.

In a case where a coating film is formed by using the coating composition, the solvent, preferably the solvent containing a liquid (L), is volatilized from the coating film made of the coating composition. By volatilizing and removing the solvent from the coating composition, a precursor layer made of the curable composition is obtained.

As a method for volatilizing the solvent, a known drying method, such as e.g. heat drying, vacuum drying or the like. The drying method may, for example, be heating and drying at 50 to 300 ° C for 1 to 120 minutes, heating and drying at 400 to 700 ° C for 1 to 60 seconds, drying at reduced pressure at 0.1 to 500 mmHg for 1 to 120 minutes, etc., be. These methods may be used in combination to volatilize the solvent, that is, to dry.

curing

The curing step is a step in which the curable composition constituting the precursor layer obtained in the above (1) is cured to form a cover layer made of a cured product. The curing method is suitably selected from heating, irradiation with active energy rays, and a method of combination thereof, depending on the kind of the curable composition used, particularly the kind of groups (F) in the fluorinated polymer (A).

In a case where the groups (F) in the fluorinated polymer (A) are composed of only -R ^f1 CO-OR ⁵ , it is considered that the crosslinking reaction is carried out by heating, especially that of the crosslinking reaction by heating at 300 ° C or lower, difficult to expire. Therefore, in such a case, it is preferable to perform the curing step by irradiation with active energy rays. In a case where the groups (F) in the fluorinated polymer (A) -R ^f1 contain CONR ¹ NR ² H or -R ^f1 C-ONR ³ OR ⁴ , it is preferable to carry out the curing step by heating, irradiating with active Perform energy beams or a combination thereof. In a case where the groups (F) in the fluorinated polymer (A) are a combination of -R ^f1 CONR ¹ NR ² H and -R ^f1 COOR ⁵ , it is preferable to carry out the curing step by heating.

By the curing method of irradiating active energy rays, a cured product, i.e., a capping layer, can be obtained at a lower temperature than by the curing process by heating. Consequently, in a case where a low-temperature treatment is required as a method of forming a cap layer, the curing method by irradiation with active energy rays is preferable. In a case where both heating and irradiation with active energy rays are to be performed, heating may be performed before, simultaneously with and / or after irradiation with active energy rays.

(Wärmeaushärtungsbedingungen)

When the precursor layer is heat-cured, the heating temperature is not particularly limited as long as it is a temperature at which the curable components in the curable composition, particularly the groups (F) in the fluorinated polymer (A), undergo a crosslinking reaction. The heating temperature is preferably in a range of 100 to 300 ° C. Incidentally, in any of the following cases, it is more preferable that the heating be carried out in an atmosphere of an inert gas such as an inert gas. Nitrogen, is carried out to accelerate the reaction.

For example, in a case where the fluorinated polymer (A) contains two kinds of groups (F), that is, -R ^f1 CONR ¹ NR ² H and -R ^f1 COOR ⁵ , the heating temperature is preferably from 100 to 200 ° C , more preferably from 120 to 180 ° C. The heating time depends on the temperature, but is preferably from 10 minutes to 10 hours, more preferably from 30 minutes to 4 hours. A method of gradually increasing the temperature is also effective.

In a case where the fluorinated polymer (A) -R ^f1 contains CONR ¹ NR ² H as groups (F), the heating temperature is preferably from 150 to 300 ° C, more preferably from 200 to 260 ° C. The heating time depends on the temperature, but is preferably from 1 minute to 10 hours, more preferably from 1 to 5 hours, still more preferably from 2 to 4 hours. A method of gradually increasing the temperature is also effective.

In a case where the fluorinated polymer (A) -R ^f1 contains CONR ³ OR ⁴ as groups (F), the heating temperature is preferably from 50 to 250 ° C, more preferably from 70 to 120 ° C. The heating time depends on the temperature, but is preferably from 1 minute to 10 hours, more preferably from 1 to 5 hours, still more preferably from 2 to 4 hours. A method of gradually increasing the temperature is also effective.

(Curing conditions of irradiation with active energy rays)

In a case where the precursor layer is cured by irradiation with active energy rays, the wavelength of the active energy rays is not particularly limited as long as it is a wavelength at which the curable components in the curable composition, especially the groups (F) of the fluorinated Polymer (A), subject to a crosslinking reaction. The wavelength of the active energy rays is preferably from 150 to 300 nm, more preferably from 200 to 260 nm. The generation source of the active energy rays may be a metal halide lamp for 250 to 300 nm, a low pressure mercury lamp for 185 and 254 nm, an excimer lamp for 172 nm and 222 nm, a KrF excimer laser for 248 nm, an ArF excimer laser for 193 nm, or an F ₂ laser for 157 nm.

By adjusting the irradiation time according to the irradiation intensity of the active energy rays, the curable composition containing the fluorinated polymer (A) can be cured to form a capping layer. For example, the crosslinking may be performed by irradiating active energy rays having an irradiance of 0.1 to 500 mW / cm ² for about 1 minute to 10 hours. By irradiating active energy rays having the above specific wavelength, the crosslinking reaction can be carried out without using a photoinitiator. Incidentally, in view of accelerating the reaction even in the case of irradiating with active energy rays, it is preferable to carry out the irradiation in an atmosphere of an inert gas such as nitrogen.

The electric wire of the present invention has a cap layer containing a cured product of the fluorinated polymer (A). The curing of the fluorinated polymer (A) can be easily performed by heat or light curing without requiring any device, and hence the productivity of the electric wire will be high.

For example, in the electric wire of the present invention, when the dielectric strength of the cured product of the fluorinated polymer (A) is 20 kV / mm or more, the cap layer has very good insulating properties. Since the cured product of the fluorinated polymer (A) has a crosslinked structure, the cap layer has excellent strength and heat resistance. Since the cap layer has the above properties, the electric wire of the present invention has excellent reliability.

The use of the electric wire of the present invention is not particularly limited. Since the electric wire of the present invention has excellent insulating properties and heat resistance, it is known as a high-voltage electric wire, an electric communication wire, an electric wiring wire used in a motor, a generator, a blast furnace, an electric furnace, an electric heater medical device, an electric scalpel, a motor vehicle, a rail vehicle, an aircraft, a steelworks, a power plant, etc., or is suitable as an electric wire used in particular at high temperatures, such as as a substrate for wireless communication using high frequency waves, millimeter waves, etc.

[Kitchen sink]

The coil of the present invention is obtained by forming the electric wire of the present invention into a coil shape. The coil of the present invention can be used in fields where very good insulating properties and very good heat resistance are required, e.g. in various electrical and electronic devices. For example, the coil of the present invention may be used for a motor, a transformer, a power transmission coil or a power receiving coil for a wireless power supply, etc., and may constitute a high power electric / electronic device. The core wire of the coil can be used as a single wire or as a twisted wire.

As a method of forming the electric wire into a coil shape, a known method can be used without any particular limitation. In particular, the coil form stands for a spirally wound long electrical wire. In such a coil, the number of turns of the electric wire, the shape and size of the coil, etc. are not particularly limited. The coil is adjusted in a suitable manner according to the various electrical and electronic devices to which the coil is applied.

EXAMPLES

Hereinafter, the invention will be specifically described with reference to examples, but the present invention is by no means limited by the following examples. Evaluations in each example were made according to the procedures described below.

[Evaluation Method]

(Weight average molecular weight)

The weight-average molecular weight of the fluorinated polymer was obtained as the molecular weight as PMMA (polymethyl methacrylate) by gel permeation chromatography (GPC) using CF ₂ CICF ₂ CHCIF (manufactured by Asahi Glass Co., Ltd., trade name: Asahiklin AK-225G ) for the fluorinated polymer P1 and tetrahydrofuran for the fluorinated polymers Q1, Q3, Q4 and R1, R3 and R4 as a solvent.

(Content of fluorine atoms in the fluorinated polymer)

The content of fluorine atoms in the fluorinated polymer was obtained by ¹⁹ F-NMR.

(Relative dielectric constant, dielectric loss tangent and dielectric breakdown strength)

Using the films prepared in the respective examples, the relative dielectric constants and the dielectric loss tangents at 1 kHz and 1 MHz were measured using the LCR meter HP4284A manufactured by Agilent Technologies, Inc., a TO-19 constant temperature chamber , manufactured by Ando Electric Co., Ltd., and solid-state electrodes of the type SE-70, manufactured by Ando Electric Co., Ltd., measured. Relative dielectric constants and dielectric loss tangents at 12 GHz and 24 GHz were measured using a synthesized sweeper 8340B manufactured by YHP, a network analyzer 8510B manufactured by YHP, a cylindrical cavity resonator (material: copper, internal mirror finish), and a semi-rigid cable for signal transmission. The dielectric breakdown strength was measured by the model HAT-300-100RHO dielectric breakdown meter manufactured by Yamazaki Sangyo Co., Ltd. Measurement conditions: Temperature: 23 ± 2 ° C, Humidity: 50 ± 5% relative humidity (RH), pre-measurement time at this temperature and humidity: 40 hours or more. Ambient medium for the measurement of dielectric strength: insulating oil.

(Assessment of solubility)

To a 1 mL of a liquid was added a fluorinated polymer in an amount such that the content was 5 mass%, followed by stirring and mixing at a temperature of 40 ° C for 1 hour, and then cooling to room temperature (25 ° C) , A judgment was made depending on whether 1 mL of the obtained mixture was clogged without a PTFE filter having a pore size of 0.5 μm and a diameter of 25 mm was filterable or not. The judgment was "solved" when filtration was possible and the judgment was "not solved" when filtration was not possible.

[Units]

The units referred to in the following Preparation Examples are as follows:

(Production Example 1)

A stainless steel autoclave having an inner volume of 1 L equipped with a stirrer was degassed under reduced pressure, and then 0.8 g of a 50% by mass solution of a polymerization initiator, perbutyl PV (tert-butyl peroxypivalate), was prepared Nippon Oil Co., Ltd.) in Asahiklin AK-225G (manufactured by Asahi Glass Co., Ltd.), 48.5 g of CF ₂ = CFOCF ₂ CF ₂ CF ₂ COOCH ₃ (hereinafter referred to as MPVB), 795 g CF ₂ = CFOCF ₂ CF ₂ CF ₃ (PPVE) and 39.4 g of Asahiklin AC-2000 (manufactured by Asahi Glass Co., Ltd.). Further, 120.3 g of CF ₂ = CF _{2 was} injected, and then the internal temperature was raised to 60 ° C, so that polymerization was carried out for 4 hours. During this period, an additional 46.4 g of CF ₂ = CF ₂ (TFE) was added to maintain the pressure at 1.01 MPa gauge.

The autoclave was cooled and the gas was purged, after which 600 g of the contents were added to a glass beaker containing 6 L of hexane. After removing the upper layer, the lower layer was heated under reduced pressure to remove residual monomeric components to obtain 103.3 g of a fluorinated polymer P1. The composition of the units in the fluorinated polymer P1, which was calculated by ¹ H-NMR and ¹⁹ F-NMR, was as follows: Units (U1a-1): Units (U2-1): Units (U3-1) = 2:71:27 (molar ratio), the weight-average molecular weight was 34,000, and the fluorine atom content was 64 mass%.

(Example 1)

The fluorinated polymer P1 obtained in Production Example 1 was hot-pressed at 80 ° C to obtain a transparent film. The transparent film was irradiated with a 200 W low-pressure mercury lamp for 2 hours in a nitrogen atmosphere and then inverted and irradiated for further 2 hours to obtain a cured film FP1 without foaming. The IR measurements showed that the absorption at 1794 cm ^-1 had almost disappeared due to C = O of the -COOCH ₃ group. The electrical properties of the cured film FP1 are given in Table 1. FP1 showed insulating properties comparable to those of a fluororesin used in conventional extrusion molding.

Further, the fluorinated polymer P1 was dissolved in Asahiklin AC-2000 so as to form a 10 mass% solution, and a copper wire having a circular cross section (1.5 mm in diameter) was dipped in this solution and then pulled up to remove the Apply P1 solution to the copper wire. Next, the copper wire is dried at 50 ° C for 1 hour and at 70 ° C for 1 hour, then irradiated with a 200 W low-pressure mercury lamp for 2 hours in a nitrogen atmosphere, and then inverted and irradiated for a further 2 hours, whereby electrical wire with excellent insulating properties, which is covered with the cured fluorinated polymer is obtained.

(Production Example 2)

26.5 g of the fluorinated polymer P1 obtained in Production Example 1 was dissolved in 129.1 g of Asahiklin AC-2000, and then 4.0 g of methanol and 0.4 g of a 79 mass% aqueous solution of hydrazine monohydrate were added thereto 2 days at 40 ° C was stirred. The reaction solution was transferred to a Petri dish, pre-dried in air, and then dried under vacuum at 100 ° C for 1 day to obtain a fluorinated polymer Q1. It was confirmed by the IR measurements that the absorption at 1794 cm ^-1 due to C = O of a -COOCH ₃ group was almost disappeared and the absorption at 1705 cm ^-1 due to C = O of a -CONH group newly occurred is.

From the results of the IR measurements and the analytical results of the fluorinated polymer P1, it was found that the composition of the fluorinated polymer Q1 is as follows: Units (U1b-1): Units (U2-1): Units (U3-1) = 2:71:27 (molar ratio), the weight-average molecular weight was 34,000, and the fluorine atom content was 64 mass%.

(Example 2)

The fluorinated polymer Q1 obtained in Production Example 2 was hot-pressed at 160 ° C to obtain a transparent film. The transparent film was heated at 200 ° C for 3 days and heated at 260 ° C for 5 hours in a nitrogen atmosphere, whereby a cured film FQ1 without foaming was obtained. The electrical properties of the cured film FQ1 are given in Table 1. FQ1 showed insulating properties comparable to those of a fluororesin used in conventional extrusion molding.

Further, the fluorinated polymer Q1 was dissolved in Asahiklin AC-2000 so that a 10 mass% solution was formed, and a copper wire having a circular (1.5 mm diameter) was dipped in this solution and then pulled up so that the Q1 solution was applied to the copper wire. Next, the copper wire was dried at 50 ° C for 1 hour and at 70 ° C for 1 hour and then heated at 200 ° C for 1 hour and at 260 ° C for 5 hours in a nitrogen atmosphere, so that an electric wire with excellent Insulation properties, which was covered with the cured fluorinated polymer, was obtained.

(Production Example 3)

MPVB and TFE were combined with the in WO 2012/157715 polymerized to synthesize a fluorinated polymer P2 having units (U1a-1): units (U2-1) = 14:86 (molar ratio). The fluorine atom content of the fluorinated polymer P2 was 69 mass%.

(Example 3)

The fluorinated polymer P2 obtained in Production Example 3 was hot-pressed at 300 ° C to obtain a transparent film. The transparent film was irradiated by a 200W low-pressure mercury lamp for 2 hours in a nitrogen atmosphere and then inverted and irradiated for further 2 hours to obtain a cured film FP2 without foaming. The electrical properties of the cured film FP2 are given in Table 1. From these data, it can be seen that FP2 showed insulating properties comparable to those of a fluororesin used in conventional extrusion molding.

Further, a powder of the fluorinated polymer P2 was dispersed in FLUTEC PP11 (manufactured by F2 Chemicals Corporation, Tetracosafluortetradecahydrophenanthrene) to form a 10 mass% dispersion in which P2 was swollen, and a copper wire having a round cross section (diameter: 1.5 mm) was immersed in this dispersion and then pulled up so that the P2 dispersion was applied to the copper wire. Next, the copper wire is dried at 200 ° C for 1 hour and at 250 ° C for 1 hour and then irradiated by a 200 W low-pressure mercury lamp for 2 hours in a nitrogen atmosphere, and then inverted and irradiated for another 2 hours, so that an electric wire having excellent insulating properties covered with the cured fluorinated polymer was obtained. Table 1 Cured foil FP1 FQ1 FP2 film thickness (Mm) 0.68 1.07 0.45 Relative dielectric constant (1 kHz) 2.02 2.18 2.77 (1 MHz) 2.00 2.15 2.62 (12 GHz) 2.03 2.03 2.21 (24 GHz) 2.07 2.13 2.23 Dielectric breakdown strength (KV / mm) 39.1 31.8 47.1 Dielectric loss tangent (1 kHz) 0.0026 0.0021 0.0064 (1 MHz) 0.0019 0.0033 0.0200 (12 GHz) 0.0026 0.0019 0.0220 (24 GHz) 0.0018 0.0014 0.0170

(Production Example 4)

A fluorinated polymer P3, which is a homopolymer of MPVB, was prepared by the in WO 2004/067655 described method synthesized. 2.6 g of P3 was dissolved in 11.5 g of Asahiklin AE-3000 (manufactured by Asahi Glass Co., Ltd.), and then 40.5 g of methanol and 1.6 g of a 79 mass% aqueous solution of hydrazine monohydrate was added, followed by stirring for 1 day at room temperature. The reaction solution was predried in a nitrogen stream and then dried under vacuum at room temperature for one day to obtain a fluorinated polymer Q3. The weight-average molecular weight of the fluorinated polymer Q3 was 5000, and the fluorine atom content was 56 mass%. Q3 was soluble in methanol.

(Example 4)

The fluorinated polymer Q3 obtained in Production Example 4 was allowed to stand at 100 ° C for 30 minutes at 200 ° C ° C for 30 minutes and heated at 250 ° C for 90 minutes in a nitrogen atmosphere, so that a cured product FQ3 was obtained. FQ3 was insoluble when immersed in methanol.

Further, the fluorinated polymer Q3 was dissolved in methanol to obtain a 10 mass% solution, and a copper wire having a round cross section (diameter: 1.5 mm) was dipped in this solution and pulled up so that Solution was applied to the copper wire. Next, the copper wire was dried at 50 ° C for 1 hour and at 70 ° C for 1 hour and then heated at 200 ° C for 30 minutes and at 250 ° C for 90 minutes in a nitrogen atmosphere, so that an electric wire, the covered with the cured fluorinated polymer.

(Production Example 5)

C (CF ₂ O (CF ₂ CF ₂ O) _k CF ₂ COF) ₄ (k = 7 on average) was characterized by that in the Japanese Patent No. 5,028,801 described method, esterified with ethanol and then dried under reduced pressure, so that a fluorinated polymer P4 [C (CF ₂ O (CF ₂ CF ₂ O) _k CF ₂ COOC ₂ H ₅ ) ₄ ] was obtained. 2.1 g of fluorinated polymer P4 was dissolved in 16.3 g of Asahiklin AE-3000, and then 2.8 g of methanol and 0.4 g of a 79 mass% aqueous solution of hydrazine monohydrate were added, followed by stirring at room temperature for 1 day has been. The reaction solution was predried in a nitrogen stream and then dried under vacuum at room temperature for one day to obtain a fluorinated polymer Q4. The IR measurements confirmed that the absorption at about 1800 cm ^-1 due to C = O of a -COOC ₂ H ₅ group had almost disappeared and the absorption at about 1700 cm ^-1 due to C = O of a -CONH Group has re-emerged. The weight-average molecular weight of the fluorinated polymer Q4 was 4000, and the fluorine atom content was 61 mass%. The fluorinated polymer Q4 was soluble in methanol.

(Example 5)

The fluorinated polymer Q4 obtained in Preparation Example 5 was heated at 100 ° C for 30 minutes, at 200 ° C for 30 minutes, and at 250 ° C for 90 minutes in a nitrogen atmosphere to obtain a cured product FQ4. FQ4 was insoluble when immersed in methanol.

Further, the fluorinated polymer Q4 was dissolved in methanol to form a 10 mass% solution, and a copper wire having a round cross section (1.5 mm in diameter) was immersed in this solution and pulled up to give the Q4 solution was applied to the copper wire. Next, the copper wire is dried at 50 ° C for 1 hour and at 70 ° C for 1 hour and then heated at 200 ° C for 30 minutes and at 250 ° C for 90 minutes in a nitrogen atmosphere, so that an electric wire, the covered with the cured fluorinated polymer.

(Production Example 6)

2.5 g of the fluorinated polymer P3 described in Preparation Example 4 were dissolved in 11.5 g of Asahiklin AE-3000, and then 23.0 g of methanol and 1.7 g of a 50% by mass aqueous solution of hydroxylamine were added thereto Room temperature for 1 day was stirred. The reaction solution was predried in a nitrogen stream and then dried under vacuum at room temperature for one day to obtain a fluorinated polymer R3. The weight-average molecular weight of the fluorinated polymer R3 was 5000, and the fluorine atom content was 56 mass%. The fluorinated polymer R3 was soluble in methanol.

(Example 6)

The fluorinated polymer R3 obtained in Production Example 6 was heated at 150 ° C for 30 minutes, at 200 ° C for 30 minutes, and at 250 ° C for 90 minutes in a nitrogen atmosphere to obtain a cured product FR3. FR3 was insoluble when immersed in methanol.

Further, the fluorinated polymer R3 was dissolved in methanol to form a 10 mass% solution, and a copper wire having a round cross section (1.5 mm in diameter) was immersed in this solution and pulled up so that the R3 solution was applied to the copper wire. Next, the copper wire is dried at 50 ° C for 1 hour and at 70 ° C for 1 hour and then heated at 200 ° C for 30 minutes and at 250 ° C for 90 minutes in a nitrogen atmosphere, so that an electric wire, the covered with the cured fluorinated polymer.

(Production Example 7)

2.1 g of the fluorinated polymer P4 described in Preparation 5 was dissolved in 15.3 g of Asahiklin AE-3000 and 5.7 g of methanol and 0.5 g of a 50% by mass aqueous solution of hydroxylamine were added followed by 4 days was stirred at room temperature. The reaction solution was predried in a nitrogen stream and then dried under vacuum at room temperature for 1 day to obtain a fluorinated polymer R4. The IR measurements confirmed that the absorption was about 1800 cm ^-1 due to C = O of a -COOC ₂ H ₅ group had almost disappeared and the absorption at about 1700 cm ^-1 due to C = O of a -CONH group has appeared new. The weight-average molecular weight of the fluorinated polymer R4 was 4,000, and the fluorine atom content was 61% by mass. The fluorinated polymer R4 was soluble in methanol.

(Example 7)

The fluorinated polymer R4 obtained in Preparation Example 7 was heated at 90 ° C for 95 minutes and at 100 ° C for 120 minutes in a nitrogen atmosphere to give a cured product FR4. FR4 was insoluble when immersed in methanol.

Further, the fluorinated polymer R4 was dissolved in methanol to form a 10 mass% solution, and a copper wire having a round cross section (1.5 mm in diameter) was immersed in this solution and pulled up so that the R4 solution was applied to the copper wire. Next, the copper wire is dried at 50 ° C for 1 hour and at 70 ° C for 1 hour and then heated at 90 ° C for 95 minutes and at 100 ° C for 120 minutes in a nitrogen atmosphere, so that an electric wire, the covered with the cured fluorinated polymer.

(Production Example 8)

5.1 g of the fluorinated polymer P1 described in Production Example 1 was dissolved in 42.8 g of Asahiklin AC-2000, and then 2.4 g of methanol and 0.2 g of a 50 mass% aqueous solution of hydroxylamine were added thereto Stirred for 1 day at room temperature. The reaction solution was predried in a nitrogen stream and then dried under vacuum at room temperature for one day to obtain a fluorinated polymer R1. The IR measurements confirmed that the absorption at about 1800 cm ^-1 due to C = O of a -COOCH ₃ group had almost disappeared and the absorption at about 1700 cm ^-1 due to C = O of a -CONH group has appeared new.

From the results of the IR measurements and the analytical results of the fluorinated polymer P1, it was found that the composition of the fluorinated polymer R1 was as follows: Units (U1c-1): Units (U2-1): Units (U3-1) = 2:71:27 (molar ratio), the weight-average molecular weight was 34,000 and the fluorine atom content was 64 mass%. The fluorinated polymer R1 was soluble in Asahiklin AC-2000 containing 3% methanol by mass.

(Example 8)

The fluorinated polymer R1 obtained in Production Example 8 was heated at 90 ° C for 95 minutes and at 100 ° C for 120 minutes in a nitrogen atmosphere to give a cured product FR1. FR1 was insoluble when immersed in Asahiklin AC-2000 containing 3% methanol by mass.

Further, the fluorinated polymer R1 was dissolved in Asahiklin AC-2000 containing 3 mass% of methanol to give a 10 mass% solution of R1 and a copper wire having a round cross section (1.5 mm in diameter). was dipped in this solution and pulled up so that the R4 solution was applied to the copper wire. Next, the copper wire is dried at 50 ° C for 1 hour and at 70 ° C for 1 hour and then heated at 90 ° C for 95 minutes and at 100 ° C for 120 minutes in a nitrogen atmosphere, so that an electric wire, the covered with the cured fluorinated polymer.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2015/129913 [0004]
• JP 4591352 [0004]
• WO 2015/098773 [0082, 0128]
• JP 5028801 [0122, 0177]
• WO 2012/157715 [0171]
• WO 2004/067655 [0174]

Claims (10)

An electrical wire comprising a conductor wire and a cover layer covering the outer periphery of the conductor wire, the cover layer being made of a cured product of a curable composition containing a fluorinated polymer containing at least three functional groups represented by the following formula (F) are shown: -R ^f1 COZ ¹ (F) (In the formula (F), R ^{f1 is} a single bond, a fluoroalkylene group or a fluoroalkylene group having at least two carbon atoms with an ether oxygen atom between carbon-carbon atoms, Z ¹ is NR ¹ NR ² H, NR ³ OR ⁴ or OR ⁵ , and R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group.) Electric wire behind Claim 1 in which the fluorinated polymer contains at least one of the functional groups represented by the formula (F) in a unit represented by the following formula (U1):

(In the formula (U1), each of X ¹ and X ² is independently a hydrogen atom or a fluorine atom, Q ¹ is a single bond or an ether oxygen atom, R ^f1 is a single bond, a fluoroalkylene group or a fluoroalkylene group having at least two carbon atoms with an ether oxygen atom between carbon Carbon atoms, Z ¹ is NR ¹ NR ² H, NR ³ OR ⁴ or OR ⁵ , and R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group.) Electric wire behind Claim 2 in which the fluorinated polymer contains at least three units represented by the formula (U1). Electric wire behind Claim 1 in which the fluorinated polymer contains at least three groups represented by the following formula (F1): - (R ^f2 O) _k -R ^f1 COZ ¹ (F1) (in the formula (F1), R ^{f2 is} a C _1-4 perfluoroalkylene group; k is an integer of 1 to 200; R ^f1 is a single bond, a fluoroalkylene group or a fluoroalkylene group having at least two carbon atoms with an ether oxygen atom between carbon-carbon Z ¹ is NR ¹ NR ² H, NR ³ OR ⁴ or OR ⁵ , and R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group.) Electric wire behind Claim 4 in which the fluorinated polymer is a compound in which three or four groups represented by the formula (F1) are bonded to a carbon atom. Electric wire after one of the Claims 1 to 5 in which the amount of fluorine atoms contained in the fluorinated polymer is from 50 to 76% by mass. Electric wire after one of the Claims 1 to 6 in which the conductor wire is made of a copper conductor or an aluminum conductor. Method for producing the electrical wire according to one of Claims 1 to 7 characterized by covering the outer periphery of the conductor wire with the curable composition for formation a precoat layer of the cap layer, and applying heat and / or radiation of active energy rays to the precursor layer to obtain a cap layer made of a cured product of the curable composition. Method for producing the electrical wire according to Claim 8 in which the precursor layer is formed by applying a coating composition comprising the curable composition and a liquid having a boiling point of at most 250 ° C to the outer circumference of the conductor wire and volatilizing the liquid from the applied coating composition. Coil formed by shaping the electric wire according to one of the Claims 1 to 7 has been formed into a coil shape.